Pressure-controlling mechanism.



J. S. MOWHIBTER. PRESSURE CONTROLLING MECHANISM.

APPLICATION FILED FEB. 4, 1909.

9, 5919535 Patented Jan. 30, 1912.

3 SHEETS-SHEET 1.

1 Q i neon-a0 J. S MQWHIRTER.

PRESSURE CONTROLLING MECHANISM.

APPLIOATION FILED IEB.4, 1909.

Patented Jan. 30, 1912.

3 SHEETS-SHEET 2.

J. s. MQWHIRTER. I PRESSURE CONTROLLING MECHANISM.

- APPLICATION FILED FEB. 4, 1909. 1,01 6,025. Patented Jan. 30, 1912.

3 SHEETS-SHEET 3.

AMMAAMA' onrrnr) STATES earns" anion.

JOHN S. MGWHIRTER, OF NEW YORK, N. Y., ASSIGNOR TO GENERAL ELECTRIG COMPANY, A CORPORATION OF NEW YORK.

PRESSURE-CONTROLLING MECHANISM.-

Specification of Letters Patent.

Application filed February 4, 1909. Serial No. 476,129.

To all whom it may concern Be it known that I, J OIIN S. MoWmn'rnn,

a citizen of the United States, residing in .the city, county, and State of New York, '5 have made a certain new and useful Invention in Pressure-Controlling Mechanism, of

which the following is a-specification. I

This invention relates to pressure controlling mechanism, and, particularly'to mechanism for automatically controlling the operation of pneumatic or air or other pumps such as are employed on street or other-liars in connection with the brake mechanism thereof.

The object of the invention is to provide a construction of controlling mechanism for air or other pumps or similar pressure mechanism, which is simple in construction and efiicient and automatic in operation.

A further object of the invention is to provide a controlling mechanism of the nature referred to which combines mechanical and electric means for the operation thereof.

A further object is to provide a controlling mechanism so constructed and arranged of contacts in an electric circuit, and an cfficient positive closing of the contacts, in the operation thereof. I

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and rela tive arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims.

. Referring to the accompanying drawings,

Figure 1 is a view in side elevation of a controllingmechanism embodying the prin- -ciples ofmy invention; Fig. 2 is a view partly in vertical longitudinal section 011 the line 2, 2, Fig. 3. Fig. 3, is a bottom plan view. Fig. i is a circuit diagram.

The same part is designated by the same reference sign wherever it occurs throughout the sever-at views.

In the operation of air compressors and other pressure producing devices, such, for instance, as are employed on street or other cars for use in connection with the brake mechanism, or other purposes, it is necessary to employ controlling devices for the compressor or pump whereby the pressure deliv-' SB cred thereby to the storage reservoir or as to effect a quick positive. opening tank may be maintained at substantially uniform degree, and so that if the tank or reservoir pressure should exceed the given point, the compressor may be automatically arrested until, by use or otherwise, the pressure in the tank or reservoir is reduced below the required minimum when the pump or compressor is automatically started again.

In controlling mechanism for accomplishing the automatic stopping and starting of the compressor or pump, it is usual to balance the pressure of the tank or reservoir against an adjustable tension, such as a spring, and so regulated as to cause the va riations in pressure in the tank or reservoir to effect the operation of switches or contacts or valves or other connections whereby the desired control of the pump or compressor operating motor is accomplished. In case an electric motor is employed for operating the pump. or compressor the controller operates on separable contacts to effect an opening or closing of the circuit of the motor. My inventionis specially designed for use in this connection and in carrying out the same I employ the balanced arrangement between the tank or reservoir pressure and an adjustable tension, such as a spring, above referred to, and I combine therewith and with each other mechanically and electrically operated devices for effecting a quick, positive opening of the contacts in the motor circuit and a positive, efiicient and quick closing of the same, in theperformance of the functions of the apparatus. t

In the drawings, reference sign 5, designates a cylinder in which operates a piston (3, exposed on one side to the pressure of the tank or reservoir, as, for instance, through pipe 7, or otherwise, and, on the other side to the tension of a spring 8, the tension of which is adjustable in any suitable or convenient manner, as for instance, by means of Patented Jan. 30,1912.

the usting nuts J, carried by fixed rods 10,

mon pivot of levers 13 end carries a contact shoe or plate 18, adapted to eotiperate with a fixed contact strip or plate 19.

Intermediate its ends the main contact lever 17 is pivotally connected as at 20, to the plunger core 21, ofa solenoid coil 22.

The auxiliary contact lever, at a point adjacent its free end is provided with an enlargement projection 23, arranged to engage or bear against the underside of the main contact lever 17, and tending, when the auxiliary lever is moved or rocked under the influence of the tension or spring 8, to move the main contact lever 17, to cause the contacts 18, 19, to close upon each other. The contacts 15, 16, controlled by the auxiliary lever 13, are arranged to separate when the lever 13 is rocked under the influence of the tension of the spring 8, and to close on each other when said lever is rocked under the influence of the pressure of the pressure medium acting against the piston 6. A blow out magnet 24, is arranged adjacent the main circuit contacts 18, 19, to perform the usual func tion of such a magnet. The circuit is com pleted from the leading-in wire to terminal 25, and thence through two paths, one to the magnet coil 22, through connection 26, and the other to the contact point 16, through connection 27. From the coil22, the circuit continues through connection 28, to the comand 17. When the latter is rocked to close the contacts 18 and 19, upon each other, the circuit continues irom said lever 17, through the contacts 18 and 19, and thence to the blow out magnet coil 24, through connections 29 and 30, to the other terminal connection 31, and thence through the motor, indicated at 32, Fig. i, and its field 33, to ground or return in the usual or any suitable manner.

The action and operation of the device is best illustrated in the diagram Fig. 1. In the arrangement of the parts as shown in this diagram the tension of spring 8, on one side of the piston 6, predominates over the pressure of the pressure medium acting against the other side of said piston, and consequently the lever 13 is rocked in a direction to engage the main contact lever 17, and rock the same in a direction to close contacts 18, 19, upon each other. This completes the circuit of the pump or compressor operating motor, and thereupon pressure medium is supplied to the tank or reservoir. As the pressure in such tank continues to build up more and more pressure will be applied to the piston 6, in a direction to 0p pose the tension of spring 8. lVhen finally, the limit of pressure to which the device is set is attained the further increase of pressure in the tank or reservoir will cause a movement of the piston which is balanced between the pressure medium and the spring 8, against the action of said spring, and in a governor is overcomes the pressure medium and moves direction to rock the lever 13, toward position to close the contacts 15, 16, upon each other. This movement of lever 13, does not in any way affect the main contact lever 17, nor the contacts contacts 15,16, are finally closed upon each other. When this point is attained the solenoid coil 22 is short circuited, current flowing from the leading in terminal 25, through connection 27, instead of connection 26, to the contact 16, thence through contact 15, lever 13, lever 17, contacts 18,19, blow out magnet 21, and on through the motor. The instant this circuit-is completed and the solenoid coil 22 is thereby short circuited, and-the core 21 of said coil is released and through gravity acting thereon, the lever 17 is quickly rocked in. a direction to separate the main cpntacts 18, 19, thereby effecting a quick opening of said contacts and consequently an arrest of the motor.

1, now, the pressure in the tank or reservoir falls below the required limit to which the adjusted the tension of spring 8,

the piston in a direction to cause the lever 13, to be rocked thereby separating the contacts 15 and 16, and causing the projection 23, to engage lever 17, and rock the latter so as to cause the contacts 18, 19, to close upon each other. The instant this occurs the cir-' cuit of solenoid 22, is again con'ipleted, whereupon the core of the solenoid is drawn into the coil sharply, thereby completing a most eflicient connection between the contacts, 18 and 19, and again starting up the motor. Thus the piston 6, balanced between the pressure medium on one side and the spring 8, on the other, the tension of the latter being ad'ustable, operates through variation of the pressure medium, to effect a rocking of the auxiliary lever 13. The rocking of this lever in one direction, under the influence of excessive pressure of the pressure medium, establishes a short. circuit around the solenoid, thereby eii'ecting, mechanically, a quick opening of the main or motor circuit, the weight of the solenoid aiding in ctfecting such quick opening. The rocking of the auxiliary lever under the influence. of the spring tension when the pressure falls, first breaks the short circuit around the solenoid, and then mechanically closes the main cir cuit including the solenoid therein, the en ergization of such coil :ausing the main contacts to be drawn together into efiicient contacting relation.

From the foregoing description it will be seen that I provide an exceedingly simple and efiicient construction which combines mechanical and electrical devices in the operationor" the governor.

lVhile I have shown the apparatus so ar ranged that gravity acts upon the solenoid core when the circuitof the coil thereot is controlled thereby until the lea short circuited to effect or assist in effecting a quick opening action of the main contacts, it will, of course, be understood that my invention, as defined in the claims, is not to be limited or restricted to this particular arrangement. It is also obvious that many variations and changes in the details of construction and arrangement of parts might readily occur to persons skilled in the art and still fall within the spirit and scope of my invention.

Having now set forth the object and nature of my invention and. a construction embodying the principles thereof, and having described such construction, its purpose, function and mode of operation, what I claim as new and useful and of my own invention and desire to secure by Letters Patent is 1. In a pressure controlling mechanism, main and auxiliary contacts, mechanical devices operated by the pressure medium for opening and closing said auxiliary contacts, mechanical connections operated by the opening of the auxiliary contacts for closing the main contacts and electric devices controlled by said auxiliary contacts for completing the closing movement of the main contacts.

2. In a pressure controlling mechanism, a movable member balanced between the pressure medium on one side and a spring pressure on the other side, main and auxiliary contacts, the pressure medium, tending to close said auxiliary contacts and the spring pressure tending to close the main contacts, a solenoid arranged, when energized, to retain the main contacts closed, the auxiliary contacts arranged, when closed, to open a short circuit around the solenoid.

In a pressure controlling mechanism, a main switch, electrically controlled means for holding said switch closed, and an auxiliary switch movable in response to variations in pressure to either mechanically close the main switch or release the holding means.

4. In a pressure controlling mechanism, a. main switch, an electromagnet arranged to closed, a pivoted auxiliary switch movable in response to a decrease in pressure to me chanically close the main switch and in re sponse to an increase in pressure to release the main switch and short circuit the electromagnet.

6. in a pressure controlling mechanism, a main switch biased to open position, an electromagnet arranged to be energized by the closing of the mainswitch for holding said switch closed, an auxiliary switch movable in response to variations in pressure, and connections whereby said auxiliary switch mechanically closes the main switch when moved in one direction and. short circuits the electromagnet when moved in the opposite direction.

7. In a pressure controlling mechanism, a pivoted main switch biased to open position, an electron'iagnet arranged to be energized by the closing of the main switch for hold ing said switchclosed, an auxiliary switch pivoted concentrically with said main switch and movable in response to variations in pressure, mechanical connections between said switches whereby the main switch is closed by a movement of the auxiliary switch in one direction and connections whereby the electromagnctis short circuited by a JOHN s. Mmvunnnn.

Witnesses:

J. KLEIN, S. E. DARBY. 

